As is generally known, in various fiber optics technologies, light beams are used to propagate electromagnetic energy through fibers. The fibers are cylindrical strands or filaments made from glass or plastic. The terms "strand," "filament," "optical fiber," and "fiber" will be hereinafter used interchangeably.
Fiber optics is based upon physics principles of refraction. Refraction is the bending of a beam or wave of light as it passes obliquely from one medium to another medium of density different than the first. There is a principle of refraction known as "total internal reflection." Total internal reflection means that light is "reflected" rather than "refracted." When a beam of light is incident to an interface between two mediums at an angle greater than the "critical angle," the beam is said to undergo "total internal reflection." The "critical angle" is the angle at which light striking the interface is not refracted or reflected but travels along the interface. When light strikes the interface at an angle less than the critical angle refraction occurs. When light strikes the interface at an angle greater than the critical angle, all of the light is reflected back through the same medium, that is to say, "total internal reflection" occurs.
As a beam of light is continually reflected at angles of incidence greater than a critical angle of the medium, light (and the electromagnetic energy which it carries) is propagated along the length of the fiber. If light is refracted outside of the fiber, the light and the electromagnetic energy which it carries are not propagated along the fiber as desired. Necessary angles of incidence will be maintained within proper limits as long as the inner surface of the fiber is essentially smooth, is continuous and does not contain sharp angles. Thus, the fiber itself must be continuous and not bent at sharp angles.
To create a fiber of desired length it is often necessary to join distinct segments of fiber to one another by fusing their end surfaces together. This process is commonly referred to as "splicing." The fusing agent in splicing is very often a laser beam which is focused upon the two end surfaces of strands which are to be joined.
A problem that arises in splicing optical fibers is that it is difficult to align and maintain alignment of the end surfaces which are to be joined so that the resulting spliced fiber is continuous and not bent at sharp angles.
The problem of maintaining fibers in precise alignment is even more significant when they are to be fused by a laser beam. In the typical situation of fusion by laser, fusion is accomplished by placing the two ends of optical fibers to be spliced at the focal point of the laser. Thus, it is very important that the ends to be spliced be properly aligned with respect to the laser as well as with respect to one another. If multiple splices are to be performed, the operation will not be efficient unless each pair of strands can be quickly and accurately aligned for fusion.
A current known method of aligning and securing optical fibers for splicing is not reliable or efficient. That method comprises placing a strand in an arbitrarily-sized groove in a metal base. If the groove is too large or too small, the fiber will not be adequately secured. The metal base is not secured and may be accidentally moved, disrupting alignment. The strand is secured by placing a magnetic weight over the strand. Magnetic attraction between the weight and base is usually either too small to adequately secure the fiber or too great to allow for ease of removal or manipulation of the weight. This method and apparatus employed does not optimally secure an optical fiber for alignment and splicing, does not enable pairs of end pieces to be easily and quickly secured and aligned with respect to each other and with respect to the laser beam, and does not provide for reliable, repeatable splicing.